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AIXpert Blog

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AIXpert Blog is about the AIX operating system from IBM running on POWER based machines called Power Systems and software related to it like PowerVM for virtualisation, PowerVC for Deploying VM's and PowerSC for security plus performance monitoring and nmon

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Inspired by this TED Talks Video on Leadership TED Talk by Simon Sinek Topic: How Great Leaders Inspire Action 18 minutes long http://www.ted.com/talks/simon_sinek_how_great_leaders_inspire_action.html It tells us to start with Why? To win hearts and minds. And not explain What? or How? until the Why? is very clear. I thought I would make an attempt: Why POWER8? We believe server sprawl means a future in which we drown in small computers taking 80% of the worlds electricity to run their idle loops 80% of the time. We believe we have got... [More]

Please provide comments on this blog entry - I want to know where I have it wrong? With IBM's massive investment in Linux on Power my brain hurts trying to express the advantages. This is because the technology is excellent but the bits you want depend on where you are coming from. So I have tried to break out potential users in to various types. For the record I am an Ab Linux on POWER User type! A - Current AIX and POWER user Already understands the POWER infrastructure, AIX and/or IBM i and are adding a new operating system... [More]

IBM announced lots of Power Systems software yesterday but the official announcements are pretty thin on the details. I have many Twitter tweets asking "What the heck does that all really mean?" and the official statements are marketing messages and not technical information like: How do you get that working? What are the pre-reqs? What are the actual commands? What does the Graphical User Interface look like? How does that help me as a System Admin person? How, in the 21st century, IBM can announce a... [More]

I got asked these questions recently and had to go look the subject up ... again! I seem to have forgotten some of the details and then I thought I would use some new features of AIX for the second part. In the distant past there was various way to stop core files being dumped in to the current working directory of the program that failed. In AIX 5.3, AIX 6 and 7, the "chcore" command does all the hard work for us by letting us Choose a specific directory for core files - which is best in it own filesystem so it can't... [More]

A very nice chart from Richard Milton of IBM on the minimum levels for AIX and VIOS of Power7 and Power7+ hardware. Download as a PDF: AIX_Levels_on_POWER7_Hardware_2013_06_20.pdf We will try to update this as new machines arrive.

POWER Relative Performance (rPerf) is often used as a way to approximate the expected difference in performance between two Power Systems servers. Although rPerf is a useful tool, it is important to understand the limitations of using rPerf to provide an estimate the performance of your specific workloads in your particular environment with a new server, First, rPerf numbers, like any published benchmark, represent the best case result when the application, configuration and system resources are all optimized -- factors that are likely not... [More]

Just completed the move of the POWER and AIX Hands-on Movies to YouTube videos - after pruning we have 97 of them. This means you can watch them on your mobile Smartphone and Tablets in addition to your workstation/personal computer. You can find them all here:
YouTube look for my "Nigel Griffiths" Channel http://www.youtube.com/user/nigelargriffiths This should mean they are simpler to find, search for and view. During the transfer I pruned out a few of the older ones particular Systems 6.2 as we now have a set of Systems... [More]

I got another WPAR question today: From the Global AIX, I can add a filesystem to /wpars/WPARname/directory so the WPAR has access but what if I don't want to have the filesystem mounted there in the Global AIX? For example: I have a Global AIX filesystem called /tools that I want to mount in to one or many WPARs and appear and /temp in the WPAR(s)? My first answer is well you can use NFS because I do that all the time and I am a heavy user of NFS - no jokes please. I use NFS heavily! If the NFS server exports the mount point for every... [More]

I thought I should summarise the long eleven part Local, Near & Far POWER7 Affinity series. 1) Placement: Find out the layout of your boxes CPU and RAM and if the RAM is evenly distributed across available DIMMs Find out the placement of your Virtual Machines (LPARs) with lssrad -av - or - topas -M 2) SMT4 : Expect POWER7 SMT4 CPU use to “look” different POWER5 & 6 have two equal threads POWER7 shuts down threads 3 & 4 and even thread 2 - when there is not enough processes running. 3) Entitlement : Only set minimum Entitlements,... [More]

I just realised that I got help from the AIX developers to explain the output of the mpstat -d command for my POWER7 and Affinity Technical University sessions in Miami and Copenhagen that I never passed on to every one. In an earlier blog we examined some mpstat columns but skipped others. The nearly undocumented mpstat stats are: S0rd, S1rd, S2rd, S3rd, S4rdand S5rd. In the AIX manuals it states: S0rd = The percentage of thread re-dispatches
within the scheduling affinity domain 0.
And likewise for the other numbers - but what does... [More]